Classification of Overhead transmission line based on length, and voltage

by eees.in · June 4, 2021

When the length of the line is up to about 50 km, the line considers as a short transmission line. The line voltage is less than 20 kV. The capacitance effect in short overhead line is neglected. Because due to the small length and lower voltage, the capacitance effect is very small. Hence, in short, overhead transmission line, the capacitance effect is neglect. Therefore, while designing, modeling and studying the performance of the short line, only resistance and inductance are taken into account.

When the length of the line between 50 km to 150 km and the line voltage is between 20 kV to 100 kV, this type of overhead line consider as a medium transmission line. In this type of line, the capacitance effect cannot be neglect. Hence, while studying the performance of the line, the capacitance effect must include.

When the length of the transmission line is more than 150 km, the line considers as a long transmission line. In this type of transmission line, the voltage is more than 100 kV. For the modeling and designing of the long overhead transmission line, the capacitance effect is taken as uniformly distribute over the entire length of the line.